The following code example demonstrates how to handle the NodeMouseDoubleClick event and how to use the TreeNodeMouseClickEventArgs. To run this example, paste the code into a Windows Form that contains a TreeView named treeView1. Populate treeView1 with the names of files located in the c:\ directory of the system the sample is running on, and associate the NodeMouseDoubleClick event of treeView1 with the treeView1_NodeMouseDoubleClick method in this example.

// If a node is double-clicked, open the file indicated by the TreeNode. void treeView1_NodeMouseDoubleClick(object sender, TreeNodeMouseClickEventArgs e)
{
try
{
// Look for a file extension. if (e.Node.Text.Contains("."))
System.Diagnostics.Process.Start(@"c:\" + e.Node.Text);
}
// If the file is not found, handle the exception and inform the user. catch (System.ComponentModel.Win32Exception)
{
MessageBox.Show("File not found.");
}
}